Allow change assignee/milestone from MergeRequest show page

app/controllers/projects/merge_requests_controller.rb

@@ -108,8 +108,15 @@ class Projects::MergeRequestsController < Projects::ApplicationController
     if @merge_request.update_attributes(params[:merge_request].merge(author_id_of_changes: current_user.id))
       @merge_request.reload_code
       @merge_request.mark_as_unchecked
+
       @merge_request.reset_events_cache
-      redirect_to [@merge_request.target_project, @merge_request], notice: 'Merge request was successfully updated.'
+
+      respond_to do |format|
+        format.js
+        format.html do
+          redirect_to [@merge_request.target_project, @merge_request], notice: 'Merge request was successfully updated.'
+        end
+      end
     else
       render "edit"
     end

app/views/projects/issues/_issue_context.html.haml

@@ -4,7 +4,7 @@
     \ and currently assigned to
 
   - if can?(current_user, :modify_issue, @issue)
-    = project_users_select_tag('issue[assignee_id]', placeholder: 'Select a user', class: 'custom-form-control', selected: @issue.assignee_id)
+    = project_users_select_tag('issue[assignee_id]', placeholder: 'Select assignee', class: 'custom-form-control', selected: @issue.assignee_id)
   - elsif issue.assignee
     = link_to_member(@project, @issue.assignee)
 

app/views/projects/merge_requests/show/_context.html.haml

+= form_for [@project, @merge_request], remote: true, html: {class: 'edit-merge_request inline-update'} do |f|
+  Created by #{link_to_member(@project, merge_request.author)} 
+  - if merge_request.assignee
+    \ and currently assigned to
+
+  - if can?(current_user, :modify_merge_request, @merge_request)
+    = project_users_select_tag('merge_request[assignee_id]', placeholder: 'Select assignee', class: 'custom-form-control', selected: @merge_request.assignee_id)
+  - elsif merge_request.assignee
+    = link_to_member(@project, @merge_request.assignee)
+
+
+  .pull-right.hidden-sm.hidden-xs
+    - if merge_request.milestone
+      - milestone = merge_request.milestone
+      %cite.cgray Attached to milestone
+
+    - if can?(current_user, :modify_merge_request, @merge_request)
+      = f.select(:milestone_id, milestone_options(@merge_request), { include_blank: "Select milestone (none):" }, {class: 'select2 select2-compact'})
+
+      = hidden_field_tag :merge_request_context
+      = f.submit class: 'btn'
+    - elsif merge_request.milestone
+      = link_to merge_request.milestone.title, project_milestone_path

app/views/projects/merge_requests/show/_mr_box.html.haml

@@ -4,15 +4,7 @@
 
   .context
     %cite.cgray
-      Created by #{link_to_member(@project, @merge_request.author)}.
-      - if @merge_request.assignee
-        Currently assigned to #{link_to_member(@project, @merge_request.assignee)}.
-    - if @merge_request.milestone
-      .pull-right
-        - milestone = @merge_request.milestone
-        %cite.cgray Attached to milestone
-        %strong= link_to_gfm truncate(milestone.title, length: 20), project_milestone_path(milestone.project, milestone)
-
+      = render partial: 'projects/merge_requests/show/context', locals: { merge_request: @merge_request }
 
   - if @merge_request.description.present?
     .description

app/views/projects/merge_requests/update.js.haml

+- if params[:merge_request_context]
+  $('.issue-box .context').effect('highlight');